Heat insulating furnace panel



June 21, 1932. H D H 1,864,333

HEAT INSULATiNG FURNACE PANEL Filed Oct. 7, 1930 It? I55 16 hwszkr B. ALB/71Gb;

Patented June 21, 1932 UNITED STATES PATENT OFFICE HERBERT B. ALDRICH, F BALTIMORE, MARYLAND, ASS IGNOR TO THE PEERLESS HEATER COMPANY, OF BOYERTOWN, PENNSYLVANIA, A CORPORATION OF PENNSYL- VANIA.

HEAT INSULATINGIFURNACE PANEL Application filed October 7, 1930. SerialNo. 486,962.

The form of my invention herein disclosed is designed and adapted for application to the wall ofa gas burning furnace, the panel being removable to afford access to-the gas burner to clean the latter.

Of course, it is not broadly new to provide a furnace with heat insulating means at its wall. However, so far as I am aware, the removable clean-out panels or doors of such furnaces in the prior art have been so constructed and arranged that suflicient heat is transferred from the combustion chamber to the outer surface of the panel or door to burn ofl' any paint finish applied thereto; ne-

cessitating the frequent recoating of the panel to eliminate the unsightly appearance thereof due to such burning.

Therefore, characteristic features of the form of my invention herein disclosed are,

first, that the panel includes inner and outer metallic frame members which are separated, in spaced relation from each other, by insulating material which is retained between them; so that there can be no direct heat transference from the inner frame member to-the outer frame member; and, second, that part of said heatinsulating material in the panel is utilized to seal the joint between the panel frame and the side wall of the furnace which supports it and thus prevent heat transference from said side wall to the outer frame member of the panel. The effect of such construction is that the original finish coatingmaterial-applied to the furnace and its appurtenances is as durable upon such panel as upon other parts of the furnace.

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

In said drawing, Fig. I is an elevation of a gas-fired furnace provided with a panel constructed and arranged in accordance with my invention. 7

Fig. II is a fragmentary sectional view of said structure, taken on the line II, II in Fig. I, but shown on a larger scale.

In said figures, the furnace wall -1 has the opening 2 surrounded by the cast metal door frame 3 which is secured in stationary relation therewith. Said frame 3 has theoutwardly extending annular flange 4 forming a closure seat'surrounding the opening 6 to receive the panel embodying'my invention which forms a removable closure for said opening 6. Said panel comprises the inner hollow frame plate 7 having the outwardly flared annular flange 8 which is nearly coextensive with the opening 6 so that it may be loosely fitted therein.

Said panel frame plate 7 is adapted to contain a sheet of insulating material 10 which may be an aggregate of asbestos or mineral wool fibers or other suitable heatinsulating material. Said sheet 10 is made of such dimensions that it is supported in spaced relation with the inner surface of said frame plate? by engagement at its edges with the inclined flange 8, upon which it is tightly pressed when the panel isassembled, as hereinafter described. .When thus assembled, there is a dead air space 11 between said frame plate 7 and said insulating sheet 10.

Said heat insulating material 10 is supplemented by the sheet 13 which is preferably formed of a closely matted aggregate of asbestos fibers. Said sheet 13 projects on all sides beyond said frame plate flange 8 so as to form a gasket which overlaps and bears upon said flange l of the wall frame 3 and is supported and protected by the outer panel frame 15, conveniently formed of cast metal having air slots 16 and 17 respectively at the top and the bottom thereof. Said panel frame member 15 has the annular shoulder 18 adapted to bear upon said insulating gasketsheet 13, in opposition to said wall seat 4, and also has the inwardly extending lip 20 covering the edge of said gasket sheet 13.

Said openings 16 and 17 extend thru theannular flange 22 of said outer panel frame 15, which flange 22 is in spaced relation with the outer surface of said insulating gasket sheet 13 forming an air chamber 23 between them. Said frame has the extensive central'opening 25 which is covered by the thin sheet metal plate 26, which is held in rigid relation with said panel frame member 15 by' the screw bolts 28' and 29, which carry nuts 30, in the air space 23, and bearing upon the inner surface of said thin metal plate 26, which is painted at its surface 27.

As indicated in Fig. II; said bolts 28 may terminate in the air space 23, but said bolts 29 extend thru the insulating sheets 13 and 10 and thru the inner panel plate 7 and are provided at the inner face of the latter with nuts 32 by which all of the members of the panel above described are held in the assembled relation shownin Fig. II. I

The heat insulating panel above aeseribea may be detachably secured upon the furnace Wall 1, by any convenient means, adapted to seal the joint between them by compression of said gasket sheet 13. For instance, such gneans may include screw bolts 34 extending {thru said furnace wall 1 and the annular door frame 3 and having clamp blocks 35 exterior thereto with flanges 36 overhanging the marginof said outer annular panel frame plate 15, as best shown in Fig. II. Said wall 1 may inclose a series of gas hurners 38 with flames 39 in cooperative reation with a series of water containers 40 and accessible thru said opening 6. An ordinary closure will remain so hot, during the operation of the furnace, that the furnace operator may be burned by accidental contact therewith. However, my closure is advantageous in that the outer atmosphere is perinitted to circulate inwardly from the air openings 1? andupwardly in the space 23 and outwardly thru the air openings 16; with the effect of maintaining the panel frame 15 and the sheet metal plate 26 secured therein, continually at such low temperature as to permit them to be handled withoutinjury to the operator; so that, whereas, with devices of the prior art; it is necessary to wait a considerable length of time after the burners 38 are shut 'ofli'be fore the removable closure may be safe- 1y handled; panel closures constructed in accordance with my invention may be immediately removed by the'operator without danof burning the latter.

Removal and replacement of such closures is facilitated by using bolts 34 formed of brass or other. non-ferric metal, to avoid the corrosion which is incident to the use of ferric metal bolts in furnace structures. For the same reason; I also prefer to form the bolts 28 and 29 and all of the nuts of non-ferric metal, tho, of'co'urse, they maybe formed of other material.

Altho I have shown but one commercial form of my invention, wherein the door and panel frames are of substantially rectangular configuration it is obvious that various modifications may be made in thestracture above described, without departing from the essential features of my invention, as defined in, the appendedclaim's.

I claim: I

- 1. 111a heat insulating panel, the combination of an inner plate of metal, an outer plate of metal, insulating material, between said plates, said insulating material holding said plates apart in insulated spaced relation,

and means holding said plates in assembled material and the respective plates.

4. A structure as in claim 1; wherein the insulating material is held in relationwith both the inner and buter metal plates 'aflbrdingair chambers between said insulating material and the respective plates; one of said chambers being sealed to prevent circulation. of air there'thru, and the other of said chambers having openings communicating with the router atmosphere toperm-it the 'circulation of air therethru.

5. A structure as in claim 1; wherein the J insulating material extends outwardly beyond the mar-gin of the inner .plate and forms a gasket adapted to seal :the joint around said panel between it and a supporting structure and prevent heat transference from said structure to the 'outerplate of saidpanel.

6. In a heat insulating panel, the combination -of an inner plate of metal, an outer plate .of metal, insulating material between said plates, said insulating material holding "said plates apart. in spaced relation, and means holding said plates in assembled relation with said insulating material, including an annular frame for said miter plate, "overlapping the latter and overhanging the edge of the insulating material; said insulating material projecting beyond the edge of said inner plate andforminga gasketsupported at it'sgouter-surface by said frame.

7; The combination with awall member including an. anhularframe for an opening therein; said frame having an outwardly projecting seat; of a heat. insulating panel, adapted to wrei'novably seal said opening, eluding an inner metal plates-an outer metal plate; heat insulating material between. said plates, and means connect-ing's'ai-d plates and insulating :materialin assembled relation; said outer plate beingiadapted to overlie saidfseat and said insulating material 'extending beyond the edge of-said inner plate and forming a gasket adapted to "overlie said seat; whereby said outer plate forms a rigid backing for said gasketiand the latter is adapted to both seal the joint between said wall frame and panel and {prevent heat transferencejbetween them; andaneans adapted to 'detachably connect said panel with said will ra e. '1'. .-f.

8. The combinatidn'jwith a furnacewa-ll having an opening therein; of a removable closure for said opening, including inner and outer metallic plates, heat insulating material between said plates, and means securing said plates and insulating material in assembled relation'; said insulating material projecting beyond the edges of said inner plate and forming a gasket backed by said outer plate; and means adapted to detachably secure said closure upon said wall with said gasket sealing the joint between them and heat insulating said outer plate from said wall, said means including separable clamp blocks adapted to engage the edge of said closure, and screw means connecting said clamp blocks with said wall.

9. A structure as in claim 8; wherein the outer metal plate is in spaced relation with the insulating material, with an air chamber between them, -'in communication with the outer atmosphere at the top and bottom thereof; whereby circulation of air thru said chamber by convection prevents injurious heating of said outer plate.

In testimony whereof, I have hereunto signed my name at Boyertown, Pennsylvania, this 2d day of Sept, 1930.

HERBERT B. ALDRICH. 

